Clear PCB manufacturing requirements help turn a finished circuit layout into a reliable physical board. Incomplete fabrication notes can create delays, material substitutions, hole-size errors or inconsistent electrical performance. This guide explains what designers and buyers should supply when ordering standard or high-frequency circuit boards.
1. Design files and revision control
Begin with a consistent manufacturing package: board part number and revision, Gerber or ODB++ outputs, NC drill files, the board outline, stackup, and an approved fabrication drawing. Include solder mask, legend and copper layers for both sides where relevant. Confirm that every export belongs to the same revision.
For controlled-impedance or multilayer designs, a stackup document and impedance table should accompany the electrical files. Do not assume that a manufacturer can infer dielectric thickness or target impedance from track appearance.
[Suggested image: PCB manufacturing documentation showing Gerber layers, drill data and stackup.]
2. PCB laminate and layer stackup
Specify the exact material grade rather than only a generic family such as FR4, Rogers or PTFE. Include the laminate manufacturer, core thickness, bonding material, copper foil and finished board thickness. For RF designs, check dielectric constant (Dk), loss tangent (Df), operating frequency and any dielectric tolerances. A hybrid Rogers/FR4 stackup must identify every material and bonding interface.
3. Copper thickness and trace dimensions
Finished copper thickness is not always equal to starting copper foil thickness, because outer-layer processing can add plated copper. Nominal copper weights are approximately 17–18 μm for 0.5 oz/ft², 35 μm for 1 oz/ft², and 70 μm for 2 oz/ft². State finished-copper acceptance requirements explicitly.
State minimum trace width and spacing for both outer and inner layers. A 10/10 mil specification means a minimum 0.254 mm line width and 0.254 mm gap; it is an example design value, not a universal manufacturer capability. RF trace width must be determined from the real stackup and impedance design.
4. Drilling, plating and mechanical requirements
Identify plated through-holes (PTH), non-plated holes (NPTH), finished diameters, tolerances, and any via filling, plugging or tenting instructions. Clarify whether drawing values represent drilled or finished hole size. Mechanical notes should identify contour dimensions, allowable outline deviation, routed cutouts, mounting-hole positions and connector-related constraints.
5. Solder mask, silkscreen and surface finish
Record solder mask color, mask openings and any areas intentionally left uncoated. Indicate the silkscreen sides and legend color. Select surface finish according to assembly and RF needs: ENIG, OSP, immersion silver, immersion tin or lead-free HASL each has distinct tradeoffs. For exposed microwave transmission lines, review finish-related conductor losses rather than selecting the finish for appearance alone.
6. Impedance control and panelization
Supply impedance targets, tolerances, reference layers and line types. Examples include 50-ohm single-ended traces and 100-ohm differential pairs, but customer-specific requirements take priority. When panelization is needed, define array size, tab or V-score treatment, fiducials and tooling holes, with a drawing that agrees with the fabrication data.
[Suggested image: panelized PCB drawing with tab routing, fiducials and tooling holes.]
7. Inspection and release checklist
Agree on electrical testing, material traceability, dimensional inspection, copper acceptance, impedance coupon verification when required, packaging and accompanying reports. Before release, verify all listed requirements against the latest design revision.
| Item | Check before fabrication |
|---|---|
| Design data | Gerber/ODB++, drills and approved revision |
| Materials | Exact grade, stackup, bonding system |
| Conductors | Finished copper, line width and spacing |
| Mechanical | Finished holes, outline, cutouts and tolerances |
| Finish and mask | Surface finish and specified openings |
| RF performance | Impedance targets and required inspection |
For more material details, see the Rogers RO4000 materials information, or review our high-frequency PCB design information checklist.
Frequently Asked Questions
Which files are required to manufacture a PCB?
Usually Gerber or ODB++, NC drill data, a board outline, stackup and fabrication notes. Special requirements should be documented separately.
Why is finished copper thickness important?
Plating can change outer copper thickness, affecting trace geometry and electrical characteristics.
Does every PCB need impedance control?
No. Specify it when the design depends on controlled transmission-line behavior.
Are standard drilling tolerances sufficient for RF connectors?
Not always. Check the connector manufacturer’s mechanical requirements and state the tolerances on the fabrication drawing.